Stearoyl ACP desaturase will be further purified and its kinetics of desaturation further studied. The role of catalase in the system will also be examined. Radioactive BASF 13-338 will be prepared and its stability, localization and transport will be studied in order to determine if indeed this compound is a specific 18:2 yields 18:3 inhibitor. The kinetics of 18:1 yields 18:2 yields 18:3 desaturation will be examined with protoplast systems.